- A thiourea-functionalized metal-organic macrocycle for the catalysis of Michael additions and prominent size-selective effect
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A discrete tetranuclear thiourea-based metal-organic macrocycle (MOM) with a large size was constructed by a well-designed organic ligand and nickel(ii) ions via self-assembly. Incorporating thiourea groups as hydrogen-bond donors into a metal-organic com
- Yang, Lu,Zhao, Liang,Zhou, Zhen,He, Cheng,Sun, Hui,Duan, Chunying
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p. 4086 - 4092
(2017/03/30)
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- Helical Oligourea Foldamers as Powerful Hydrogen Bonding Catalysts for Enantioselective C-C Bond-Forming Reactions
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Substantial progress has been made toward the development of metal-free catalysts of enantioselective transformations, yet the discovery of organic catalysts effective at low catalyst loadings remains a major challenge. Here we report a novel synergistic
- Bécart, Diane,Diemer, Vincent,Salaün, Arnaud,Oiarbide, Mikel,Nelli, Yella Reddy,Kauffmann, Brice,Fischer, Lucile,Palomo, Claudio,Guichard, Gilles
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supporting information
p. 12524 - 12532
(2017/09/23)
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- Divergent Reactivity of Nitrocyclopropanes with Huisgen Zwitterions and Facile Syntheses of 3-Alkoxy Pyrazolines and Pyrazoles
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A novel annulation reaction of trans-2-substituted-3-nitrocyclopropane-1,1-carboxylates with in situ generated Huisgen zwitterions is reported, providing facile synthesis of 3-alkoxy pyrazolines in good yields and high diastereoselectivities. This reactio
- Yang, Changjiang,Liu, Wei,He, Zijian,He, Zhengjie
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supporting information
p. 4936 - 4939
(2016/10/18)
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- Efficient synthesis of β-aryl-γ-lactams and their resolution with (S)-Naproxen: Preparation of (R)- and (S)-Baclofen
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An efficient synthesis of enantiomerically-pure β-aryl-γ-lactams is described. The principal feature of this synthesis is the practical resolution of β-aryl-γ-lactams with (S)-Naproxen. The procedure is based on the Michael addition of nitromethane to benzylidenemalonates, which was easily obtained, followed by the reduction of the γ-nitroester in the presence of Raney nickel and the subsequent saponification/decarboxylation reaction. The utility of this methodology was highlighted by the preparation of enantiomerically-pure (R)- and (S)-Baclofen hydrochloride.
- Montoya-Balbás, Iris J.,Valentín-Guevara, Berenice,López-Mendoza, Estefanía,Linzaga-Elizalde, Irma,Ordo?ez, Mario,Román-Bravo, Perla
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p. 22028 - 22043
(2016/01/25)
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- Multisite organic-inorganic hybrid catalysts for the direct sustainable synthesis of GABAergic drugs
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Multisite organic-inorganic hybrid catalysts have been prepared and applied in a new general, practical, and sustainable synthetic procedure toward industrially relevant GABA derivatives. The domino sequence is composed of seven chemical transformations which are performed in two one-pot reactions. The method produces both enantiomeric forms of the product in high enantiopurity as well as the racemate in good yields after a single column purification step. This protocol highlights major process intensification, catalyst recyclability, and low waste generation.
- Leyva-Perez, Antonio,Garcia-Garcia, Pilar,Corma, Avelino
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supporting information
p. 8687 - 8690
(2014/08/18)
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- An expedient and green protocol for the Michael addition of malonates, diketones and p-keto esters to the nitrostyrenes
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A novel methodology has been developed for the rapid synthesis of functionalized nitroalkanes by the addition of less reactive carbon nucleophiles such as malonate esters, acetylacetone and ethyl acetoacetate to various r/ms-p-nitrostyrenes under solvent-
- Agarwal, Jyoti,Naganaboina, Ram Tilak,Peddinli, Rama Krishna
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p. 511 - 518
(2013/06/05)
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- Iodine-promoted synthesis of 3-arylindolizine-1-carboxylates from 2-(2-nitro-1-arylethyl)malonates and pyridine
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An efficient and straightforward one-pot synthetic protocol has been developed for the synthesis of 3-arylindolizine- 1-carboxylates via 1,3-dipolar annulation of 2-(2-nitro-1-arylethyl)malonates with pyridine and subsequent aromatisation in the presence of molecular iodine. The structure of methyl 3-(4-methoxyphenyl)indolizine-1-carboxylate (2a) and methyl 3-iodo-2-(4- nitrophenyl)indolizine-1-carboxylate (2f) was further confirmed by X-ray single crystal analysis. Website
- Li, Yun,Zhou, Zhengquan,Ye, Weijian,Liu, Juanjuan,Yao, Juan,Wang, Cunde
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p. 526 - 530
(2013/10/22)
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- Immobilization of 1,5,7-triazabicyclo [4.4.0] dec-5-ene over mesoporous materials: An efficient catalyst for Michael-addition reactions under solvent-free condition
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Immobilization of 1,5,7-triazabicyclo [4.4.0] dec-5-ene (TBD, a bicylic guanidine base) over mesoporous material like SBA-15 has been found to be an excellent catalyst for Michael-addition of β-nitro styrene with malonate. The reactions were performed und
- Kalita, Pranjal,Kumar, Rajiv
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experimental part
p. 250 - 258
(2012/01/05)
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- Highly enantioselective Michael addition of malonates to nitroolefins catalyzed by chiral bifunctional tertiary amine-thioureas based on saccharides
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A series of saccharide-derived bifunctional tertiary amine-thioureas for the asymmetric Michael addition reaction have been designed and synthesized. The addition products between malonates and various nitroolefins were obtained in high yields (up to 99%)
- Li, Xiao-Juan,Liu, Kun,Ma, Hai,Nie, Jing,Ma, Jun-An
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scheme or table
p. 3242 - 3246
(2009/06/25)
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- Mechanism and application of a microcapsule enabled multicatalyst reaction
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In this paper, we describe the development and application of a multistep one-pot reaction that is made possible by the site isolation of two otherwise incompatible catalysts. We prepared a microencapsulated amine catalyst by interfacial polymerization and used it in conjunction with a nickel-based catalyst for the transformation of an aldehyde to a Michael adduct via a nitroalkene intermediate. The amine-catalyzed conversion of an aldehyde to a nitroalkene was found to proceed through an imine rather than a nitroalcohol. Kinetic studies indicated that the reaction is first order in both the nickel catalyst and the shell of the encapsulated amine catalyst. Furthermore, we provide evidence against interaction between amine and nickel catalysts and present kinetic data that demonstrates that there is a rate enhancement of the Michael addition due to the urea groups on the surface of the microencapsulated catalyst. We applied our one-pot reaction to the development of a new synthetic route for pregabalin that proceeds with an overall yield of 74%.
- Poe, Sarah L.,Kobaslija, Muris,McQuade, D. Tyler
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p. 9216 - 9221
(2008/02/11)
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- An enantioselective Michael addition of malonate to nitroalkenes catalyzed by low loading demethylquinine salts in water
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An enantioselective Michael addition of malonate to nitroalkenes is efficiently catalyzed by low loading demethylquinine salts in water; the yield range from 49% to 93% and the ee up to 90%.
- Chen, Fu-Xin,Shao, Cheng,Wang, Quan,Gong, Pin,Zhang, Dong-Yan,Zhang, Bang-Zhi,Wang, Rui
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p. 8456 - 8459
(2008/03/13)
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- Process for preparing optically active nitro compounds and cyano compounds
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[Problem] The problem of the invention is to prepare nitro compounds and cyano compounds in high efficiency and high stereoselectivity by a simple and practical Michael reaction. [Solution] A process for preparing optically active nitro compounds and cyan
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Page/Page column 21
(2008/06/13)
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- The study of reaction mechanism for the transformation of nitronate into nitrile by phosphorus trichloride
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Nitronate was generated using β-nitrostyrene and the anion of dimethyl malonate in THF at 0°C. Subsequent treatment with PCl3 in the presence/absence of DMAP either in THF or pyridine afforded nitroalkane, chloroxime, and nitrile. Pyridine, THF, and THF-pyridine co-solvent as solvents were investigated under different conditions. With different anions of malonates containing dipolarphiles, cyclic compounds were obtained as major products indicating nitrile oxides were generated during the reaction. Based on the results, compared to that of the one reported in literature, a plausible mechanism involving nitrile oxide intermediate was proposed.
- Tu, Zhijay,Jang, Yaochung,Lin, Chunchi,Liu, Ju-Tsung,Hsu, Jianming,Sastry,Yao, Ching-Fa
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p. 10541 - 10551
(2007/10/03)
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- Highly enantioselective conjugate addition of malonate and β-ketoester to nitroalkenes: Asymmetric C-C bond formation with new bifunctional organic catalysts based on cinchona alkaloids
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The development of readily accessible bifunctional chiral catalysts is a desirable yet challenging goal in catalytic asymmetric synthesis. In this communication, we describe the development of a new class of readily accessible chiral bifunctional organic catalysts that could be derived in one or two steps in high yield from either quinidine or quinine. These catalysts have been shown to catalyze a highly enantioselective conjugate addition of methyl and ethyl malonates and β-ketoesters to a broad range of β-substituted nitroalkenes, an synthetically important C-C bond-forming reaction utilizing readily available starting materials. This new catalytic asymmetric reaction proceeds in 91-98% ee and 71-99% yield. Copyright
- Li, Hongming,Wang, Yi,Tang, Liang,Deng, Li
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p. 9906 - 9907
(2007/10/03)
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